TWEED CONTRAST WITH (223) HABIT IN ARC-MELTED ZIRCONIA YTTRIA ALLOYS

An electron microscopic study was conducted on the habit planes of the tweed contrast which developed in arc-melted ZrO2-Y2O3 alloys along with the herringbone structure of the tetragonal phase. Examination of the composite structure indicated that the tweed structure formed after the herringbone structure. Trace analysis yielded a result consistent with the (223) habit plane which was predicted also in this paper from an "ellipsoidal inclusion method". Possible origins were suggested of the discrepancy in the habit planes reported by some authors of similar contrast. © 1990.